Lead extrusion apparatus



March 15, 1938. A. J. N. DUCLOS LEAD EXTRUSION APPARATUS Filed March 26, 1936 6 Luv:

. //V|/[/VTOI? 14d IV. 006108 3) ATTORNEY Patented Mar. 15, 1938 PATENT OFFICE LEAD EXTRUSION APPARATUS Aeneas J. N. Duclos, South Orange, N. J., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application March 26, 1936, Serial No. 70,909

7 Claims.

This invention relates to lead extrusion apparatus, and more particularly to heating means for the die block of lead extrusion apparatus.

An object of the invention is to provide an effective and efiicientheating means for the die block of lead extrusion apparatus.

In accordance with one embodiment of the invention, a single burner-is provided to cooperate with a shield to guide the heat around the die block from the exit end of the cable to be sheathed toward the entrance end of the cable.

Other objects and advantages will appear as the description proceeds.

A complete understanding of the invention may be had by reference to the following description taken in conjunction with the accompanying drawing, in which Fig. 1 is afront elevation of an apparatus embodying the'invention;

Fig. 2 is a sectional view taken on line 2-2 of Fig.

Fig. 3 'is'a fragmentary view of a support for the shield, and

Fig. 4 is a sectional view taken on line 44 of Fig. 3.

The invention is illustrated as applied to a conventional type of lead extrusion apparatus having a cylinder 5 which is filled with molten lead. After the lead has solidified andreached a certain degree of plasticity in the cylinder, pressure is exerted on the lead by means of a relatively movable ram 6 to force the lead through a die block 1 and cover a cable 8 with a lead sheath 9.

The uncovered-cable is fed through an aperture in an adjusting nut II for the core tube and issues with a lead sheathing through an aperture in the adjusting nut l2 for the extrusion die.

In sheathing a cable it usually requires more be mentioned the excessive pressure required to extrude the lead from the die block, and the improper welding of the lead sheath at the seam on the underside of the sheath. Means must, therefore, be provided to maintain the lead in the die block at the proper temperature at all times. 'It has been found that a greater amount of heat should be applied at that end of the die block where the sheathed cable leaves the die block. This is accomplished in the present invention by providing a pair of shields l3 which are arcuately shaped to conform to the periphery of the die block. Each of these-shields comprises an inner sheet of a heat resistant metal I4 and an outer sheet l5 of similar material between which is interposed a layer of heat insulating material such as asbestos. The forward end of this shield is provided with an end member H which does not extend downwardly as far as the shield, and is provided with an aperture l8 through which a burner l9 extends to direct a flame against the die block. Another end member 2| is provided at the rearward end of the shield and is similar to the end member I1 except that it is not provided with an aperture for a burner. The end members 2| are pivotally mounted on the shields l3 and serve to control the temperature in the spaces between the shields and the die block.

The shields rest upon an annular support formed by a pair of semi-circular members 25, through which a plurality of bolts 26' extend whose heads engage a cylindrical portion of the apparatus. Each of these bolts is provided with sleeves 21 and between the sleeves an arcuate member 28 is supported. A fiat arcuate member 29 rests upon each of the sleeves of the bolts and the ends of the arcuate members 29 are provided with eyelets surrounding the sleeves of the end bolts. Since die blocks of different sizes are sometimes used in the apparatus the shields may be placed on either the inneror outer arcuate members 29 to position them for the particular size of die block being used. For convenience in shifting the shields a pair of handles 30 is provided through which a bar may be passed to lift the shields from one position to another.

The shields may also be adjustedvertically by vertically adjusting the annular support upon which they rest.

The burner I9 is mounted upon a pair of upright arms 33 carried by a weighted block 34 which may be positioned in any desired location on the ledge 35 adjacent the die block. The burner may be clamped to the upright arms by means of a clamping plate 36 secured in place by bolts. and wing nuts to permit convenientvertical adjustment of the burner. The burner is supplied with a. combustible gas mixture through a flexible tube 31. Valves 38 are provided so that the amount of gas and thereby the size of the flame may be individually controlled for each of the burners. A pilot burner 39 may also be proangle at which the flame strikes the die block.

together with the shield causes heat to travel around the die block, and since a large portion of the heat is absorbed by the die block at the point of application of the flame, the amount of heat applied to the die block will progressively decrease toward the entrance end of the cable. The die block is preferably provided with thermocouples M as an aid to the operator in maintaining the proper temperature in the die block. If the temperature of the material in the die block becomes too high, the member 2| may be swung outwardly away from the die block to decrease the concentration of heat in the space between theshield and the die block or the amount of the combustible gas supplied to the burner may be varied. In this manner a very effective and accurate control of the temperature of the die block may be obtained to provide a uniform sheath of high quality.

In order to assist the operator to direct the flame to the proper area of the die block, a target 42 is provided on the die block and consists preferably of an area coated with aluminum painted or sprayed thereon.

It will be understood that the nature and embodiment of the invention herein disclosed is merely illustrative, and that many changes and modifications may be madetherein without departing from the spirit and scope of the invention.

block through which a cable to be sheathed with lead is passed, a burner adjacent the exit end of the cable for directing a flame in the direction of the entrance end of the cable, and a shield for guiding-the heat from the burner toward said entrance end.

' 3. In a lead extrusion apparatushaving a die block through which a cable to be sheathed with lead is passed, a burner on either side of the exit end of the cable for directing flames around the die block toward the entrance end of the cable, and a shield for each burner for guiding the heat from the burner toward said entrance end.

4. In a lead extrusion apparatus having a die block through which a cable to be sheathed is passed, a shield extending over a portion of the die block between the exit and entrance points of the cable, and means for applying a progressively higher temperature toward the exit point of the cable.

5. In a lead extrusion apparatus having a die block through which a cable to be sheathed is passed, a shield extending over a portion of the die block between the exit and entrance points of the cable, and a single burner cooperating with said shield for applying a progressively higher temperature toward the exit end of the cable.

6. In a lead extrusion apparatus having a die block through which a cable to be sheathed with lead is passed, a shield circumferentially extending around a portion of the die block, an end member extending from the shield to the die .block having an aperture therein, a burner for projecting a flame through said aperture, and a second end member pivotally mounted on the opposite end of the shield.

7. In a lead extrusion apparatus, a burner, a shield cooperating therewith to apply heat to the apparatus, and a support for said shield mounted adjacent to the apparatus comprising a plurality of annular members spaced progressively from the apparatus for selectively posi tioning the shield to regulate the application of heat to the apparatus.

' AENEAS J. N. DUCLOS. 

